Water: Why We Need It continued...

Without it, the body begins to shut down, as seen in Kiley's experience at sea. Symptoms of severe dehydration include altered behavior, such as severe anxiety, confusion, or not being able to stay awake; faintness that is not relieved by lying down; an inability to stand or walk; rapid breathing; a weak, rapid pulse; and loss of consciousness.

While striking a water balance in our bodies is something that happens naturally as we consume three meals a day coupled with beverages, most people aren't aware that the body is only one or two percentage points away from a problem.

"Very slight changes in body water may create some performance issues in sports; as little as a 2% decrease in body water can lead to dehydration and performance detriments in sports," says Kenney. "When your water levels decrease by higher levels like 3% or 4%, there are physiological changes that occur that may have health consequences, such as increased heart rate and body temperature."

What Counts?

As Debbie Kiley pointed out to the extreme, we need fluids to survive. But what counts? Does the cup of Joe every morning help, or as many believe, hinder? Contrary to the myth, yes, coffee counts when you're tallying fluid intake.

"There is no truth to the idea that coffee makes you dehydrated. That is a pervasive myth," says Kenney, who is a spokesman for the American College of Sports Medicine (ACSM). "The diuretic effect of the caffeine of soda and coffee is mild compared to the amount of fluid they contain."

So coffee and soda count in our quest to stay hydrated. What else can we add to the list?

"You don't have to drink water per se to get water, you can eat watery foods and that will count," says Nancy Clark, a registered dietitian and sports nutritionist in Boston. "Soup counts, yogurt and watermelon count. An orange is 90% water, salads are a lot of water; so all in all, people get plenty of water through foods and beverages other than water."

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